Ibanez Agustin, Herzog Ruben, Barbey Florentine, Islam Md Nurul, Rueda-Delgado Laura, Nolan Hugh, Prado Pavel, Krylova Marina, Javaheripour Nooshin, Danyeli Lena, Sen Zümrüt, Walter Martin, Odonnell Patricio, Buhl Derek, Murphy Brian, Izyurov Igor
Trinity College Dublin.
University Hospital Jena.
Res Sq. 2024 Mar 21:rs.3.rs-3954073. doi: 10.21203/rs.3.rs-3954073/v1.
In a double-blinded cross-over design, 30 adults (mean age = 25.57, SD = 3.74; all male) were administered racemic ketamine and compared against saline infusion as a control. Both task-driven (auditory oddball paradigm) and resting-state EEG were recorded. HOI were computed using advanced multivariate information theory tools, allowing us to quantify nonlinear statistical dependencies between all possible electrode combinations. Results: Ketamine increased redundancy in brain dynamics, most significantly in the alpha frequency band. Redundancy was more evident during the resting state, associated with a shift in conscious states towards more dissociative tendencies. Furthermore, in the task-driven context (auditory oddball), the impact of ketamine on redundancy was more significant for predictable (standard stimuli) compared to deviant ones. Finally, associations were observed between ketamine's HOI and experiences of derealization. Conclusions: Ketamine appears to increase redundancy and genuine HOI across metrics, suggesting these effects correlate with consciousness alterations towards dissociation. HOI represents an innovative method to combine all signal spatial interactions obtained from low-density dry EEG in drug interventions, as it is the only approach that exploits all possible combinations from different electrodes. This research emphasizes the potential of complexity measures coupled with portable EEG devices in monitoring shifts in consciousness, especially when paired with low-density configurations, paving the way for better understanding and monitoring of pharmacological-induced changes.
在双盲交叉设计中，30名成年人（平均年龄 = 25.57，标准差 = 3.74；均为男性）接受了消旋氯胺酮治疗，并与作为对照的生理盐水输注进行比较。记录了任务驱动（听觉Oddball范式）和静息状态脑电图。使用先进的多变量信息理论工具计算高阶相互信息（HOI），使我们能够量化所有可能电极组合之间的非线性统计依赖性。结果：氯胺酮增加了脑动力学中的冗余度，在α频段最为显著。冗余度在静息状态下更为明显，与意识状态向更多解离倾向的转变相关。此外，在任务驱动的情境（听觉Oddball）中，与异常刺激相比，氯胺酮对冗余度的影响在可预测（标准刺激）刺激下更为显著。最后，观察到氯胺酮的HOI与现实解体体验之间存在关联。结论：氯胺酮似乎增加了跨指标的冗余度和真正的HOI，表明这些效应与意识向解离的改变相关。HOI代表了一种创新方法，可将从低密度干式脑电图获得的所有信号空间相互作用结合用于药物干预，因为它是唯一利用不同电极所有可能组合的方法。本研究强调了复杂性测量与便携式脑电图设备相结合在监测意识转变方面的潜力，特别是与低密度配置配对时，为更好地理解和监测药物诱导的变化铺平了道路。
